Foam devices for fog nozzles



May 27, 1969 N. c. HOUT FOAM DEVICES FOR FOG NOZZLES Filed Au 7, 1967Sheet INVENTOR. Norman C.

N. C. HOUT May 27, 1969 FOAM DEVICES FOR FOG NOZZLES Sheet Filed Aug. 7,1967 air INVENTOR. Norman C. Hout 5&6

United States Patent US. Cl. 169-15 7 Claims ABSTRACT OF THE DISCLOSUREAn attachment for fog nozzles of the character employed by firemencomprising, a pair of concentric tubes or sleeves disposed in spacedrelation, the innermost tube or sleeve being shaped to form a primaryVenturi passage; the spacing between the two tubes constituting asecondary Venturi passage. A coupling for a hose and an attachment for afog nozzle is located centrally and at the mouth of the innermost tube.The outermost tube has a portion projecting beyond an end of theinnermost tube and said portion of the outermost tube contains nested,concentric frusto-conical foraminous screens of different angularity,each of the screens having a central opening, which openings are axiallyaligned, and one of the screens has a foraminous aerator tube disposedin its central opening and which tube is directed therefrom toward thecentral opening in the other screen.

The present invention relates to fog nozzle attachments for use inconnection with fire hoses and has for one of its objects the provisionof a device of this character by means of which substantial variation inthe outflow of foam or liquid can be had. It is an object of theinvention to provide a device of this character which can provide forstraight stream operation in addition to ultra high expansion flow andto secure various other flow effects and reach that are desirable andadvantageous under different operating conditions.

With these and other objects to be hereinafter set forth in View, I havedevised the arrangement of parts to be described and more particularlypointed out in the claims appended hereto.

In the accompanying drawings, wherein an illustrative embodiment of theinvention is disclosed,

FIG. 1 is a longitudinal sectional view of a device constructedaccording to the invention;

FIG. 2 is a view of the screen unit as seen from the right of FIG. 1;

FIG. 3 is a view of the outer and inner shells or sleeves as seen fromthe left of FIG. 1 and with the screen unit omitted;

FIGS. 4, and 6 are diagrammatic views showing the operation of thedevice under different fog nozzle adustments.

Referring to the drawings, 1 indicates an outer shell or sleeve oftubular form, said shell being provided with a flared end 2 co-operatingin the formation of a Venturi passage between it and the inner shell orsleeve shown at 4. The shorter inner sleeve or shell 4 is arrangedwithin and is spaced from the outer shell 1, so that there is an annularspacing 3 between it and the outer shell or sleeve 1. Both of thesleeves 1 and 4 are composed of imperforate material and the outersleeve or shell is provided on its exterior with a number of handles 5by means of which it can be conveniently handled and used.

The inner sleeve or shell 4 is supported within the outer sleeve bysuitable radial braces 6 or other supports which serve to maintain thetwo sleeves 1 and 4 in their required spaced and concentric relation.The inner sleeve 4 is flared at one end, as shown at 7 thus providingwhat is herein referred to as the primary Venturi opening ice extendingthrough it. The inner sleeve 4 extends beyond the flared end 2 of theouter sleeve and at its opposite end the outer sleeve extends beyond theinner sleeve, thus providing a projecting portion 23.

Arranged centrally of the two sleeves or shells 1 and 4 is a hosecoupling 8 to one end of which is attached the hose 9, shown in FIGS. 4to 6, and said coupling is threaded at 10 to receive a conventional fognozzle 11. The coupling 8 is supported from the inner sleeve 4 by meansof radial braces shown at 12. An in-line foam eductor is used inconnection with the fog nozzle to intro duce foam solution into thewater stream before it reaches the unit.

Mounted within the outer sleeve 1 and forwardly of one end of the innersleeve 4 is a screen unit which primarily consists of a plurality ofnested and concentrically arranged foraminous frusto-conical screens anda centrally-arranged foraminous straight-stream aerator. One of thescreens, shown at 13 and referred to as the inner cone, is a relativelyflat frusto-cone of mesh material having a central opening 14 at itsapex. The outer cone shown at 15 is also foraminous or composed of meshmaterial and is of steeper angularity and because of the difference inangularity between the two cones l3 and 15, annular spacing 16 isprovided between these two frusto-conical mesh screens. The intersticesof the mesh in the two screens may be of the same size or may be ofdifferent size in the two screens. Located at the center or apex of theouter screen 15 is a straight stream mesh tube 17 which is axiallyaligned with the opening 14 in the inner cone, but physically slightlyspaced from the inner cone. The tube 17 has a flared end 18 facing theopening 14, and said tube 17 is located in the spacing 16 between thetwo cones.

The operation of the device is diagrammatically disclosed in FIGS. 4 to6 inclusive. In FIG. 4, the foam nozzle 11 has been adjusted for thespreading or flaring action of the emanating fluid 20, and which fluidthus tends to spread upon leaving the inner sleeve or shell 4 to passthrough the screen unit and emerge as foam for wide spread or shortreach to thereby snuff out an adjacent fire. While the unit is thusoperating, air will enter through the primary Venturi passage 4 asindicated by the arrows in FIG. 4 and air will also enter through thesecondary passage 3, the siphoning action of the fluid emanating fromthe foam nozzle aiding in the securing of this effect. With the flowfrom the foam nozzle 11 adjusted for wide angle fog (approximately 60degrees or less) the flow of fluid passing through the primary Venturipassage defined by the sleeve 4 and filling the narrower end thereofcauses a lower pressure differential at the wider end of the sleeve 4,causing an inrush of air through the primary Venturi and increases thevelocity of the solution and air to enter the secondary Venturi passage3. The velocity of the solution and air passing through the screen 13causes a rapid air expansion of the foam solution. This expansion andthe forward velocity of the mixture through the screen 13 causes apressure differential at the opening of the secondary Venturi passage 3,causing more air to flow around the outside of the sleeve 4 and throughthe screens 13 and 15. This added air increases the expansion ratio ofthe expanded solution flowing through the foam screens.

When longer reach of the foam emanating from the device is required, theoperator will adjust his fog nozzle as shown in FIG. 5 to thereby narrowthe fog pattern in the throat of the sleeve 4, causing a higher flowvelocity through the screens at a reduced expansion ratio on the finaldischarge. This is shown in FIG. 5 wherein the manner in which air isdrawn into the primary Venturi or within the sleeve 4, is disclosed.

For greater reach of the output from the unit, the

operator can alter the fog nozzle pattern to a straight streamsubstantially as shown in FIG. 5. In the operation of the device in thismanner, there is considerably less air flow introduced through thescreen unit, 13, 15 and 17, causing a lower expansion ratio of thefinally discharged stream. The straight stream aerator tube 17introduces air into the straight stream of solution flowing through it.To enhance straight stream operation, the foam screens 13 and 15 musthave axially aligned central openings of appropriate size to allow thestraight stream to pass to the aerator cone.

From the foregoing, it will be apparent that there is herein disclosed afoam attachment which can be employed with various settings oradjustments of a foam nozzle, thus giving the fireman or other user moreversatility and selection of different operations, and which is of suchefiiciency that there is considerable saving in water and foam solutionper cubic foot of output, and greater safety of the fireman.

Most fire departments are provided with in-line eductors and matchingnozzles as standard equipment and can use them in connection with thedescribed device at great saving in the initial purchase cost.

What I claim is:

1. A unit for use in connection with a fog nozzle comprising, a pair ofsleeves arranged in concentric, spaced relation to thereby provide anannular spacing between them, the spacing constituting a secondaryVenturi passage, the innermost of the sleeves forming a primary Venturipassage through it, mounting means for a fog nozzle at an entrance tothe innermost sleeve, a plurality of nested, conical foraminous screenslocated in the outermost sleeve beyond one end of the innermost sleeveone of the screens having a tubular extension directed toward another ofthe screens and located between said screens.

2. A unit according to claim 1, wherein the nested foraminous screensare of different 'angularity and provide for an annular spacing betweenthem, and the outermost screen carrying the tubular extension disposedin said spacing.

3. A unit according to claim 2, wherein said tubular extension is flaredat one end and such flared end is situated adjacent to the centralportion of the screen.

4. A unit according to claim 1, wherein the screens have axially alignedcentral openings, and the tubular extension is a foraminous tube carriedby one of the screens and directed toward another of the screens and isaxially aligned with said central openings.

5. A unit for use in conjunction with a fog nozzle comprising, a pair ofsleeves arranged in concentric spaced relation to provide an annularspacing between them, said spacing constituting a secondary Venturipassage, the innermost of the sleeves forming a primary 'Venturi passagethrough it, both of the sleeves being flaredat one end, the flared endof the innermost sleeve extending beyond the flared end of the outersleeve, a hose coupling and a fog nozzle connection located centrally ofthe innermost sleeve at the entrance end thereof, so that solution fromthe nozzle will be directed through said innermost sleeve, a pair ofnested frusto-conical foraminous screens fitted in the'outer sleevebeyond one end of the inner sleeve, the screens having axially alignedcentral openings, and one of the screens being provided with a centrallylocated formaminous tube directed toward the central opening in theother tube.

6. A unit according to claim 5, wherein the foraminous tube is attachedonly to one of the screens and has a flared end directed toward anotherof the screens and is located near the central opening in said otherscreen.

7. A unit for use in conjunction with a fog nozzle comprising, a pair ofconcentric sleeves arranged one within the other and providing spacingbetween them, each of the sleeves being flared at one end, the flaredend of the innermost sleeve extending beyond the flared end of the outersleeve a fog nozzle connection located centrally of the innermost sleevebeyond the flared end thereof, radial supports extending from the fognozzle connection to said flared end, the innermost sleeve being shorterin length than the outermost sleeve so that said outermost sleeve has aportion projecting beyond the innermost sleeve remote from the flaredends of the sleeves, a plurality of centrally-apertured conicalforaminous screens situated in said projecting portion of the outermostscreen, one of the screens having a central tube in its apertureextending axially of the screens and directed toward the centralaperture in the other screen.

References Cited FOREIGN PATENTS 1,014,293 5/ 1952 France. 1,045,049 6/1953 France. 1,457,03 1 9/1966 France.

M. HENSON WOOD, J 11., Primary Examiner. MICHAEL Y. MAR, AssistantExaminer.

US. Cl. X.-R. 239-5533, 590.3

